1. Field of the Invention
This invention relates to urethane coatings and urethane adhesive compositions.
2. Description of the Prior Art
Jayawant U.S. Pat. No. 3,635,906 discloses a method of preparing polyurethanes by time-lapse catalysis which comprises mixing an organic polyisocyanate, a polyhydroxy compound, and amine-free organo tin cure rate catalyst for the polyurethane reaction, and a time-lapse modifier selected from beta-dicarbonyl compounds, alpha-hydroxy ketones, fused aromatic beta-hydroxy ketones and beta-hydroxy nitrogen-heterocyclic fused aromatics, and allowing the reaction mixture to cure at ambient temperature. Jayawant teaches that no other cure rate catalyst can be used except amine-free organo-tin.